Small dead space heat and moisture exchangers do not impede gas exchange during noninvasive ventilation: a comparison with a heated humidifier

Objective

Adverse respiratory and gasometrical effects have been described in patients with acute respiratory failure (ARF) undergoing noninvasive ventilation (NIV) with standard heat and moisture exchangers (HME). We decided to evaluate respiratory parameters and arterial blood gases (ABG) of patients during NIV with small dead space HME compared with heated humidifier (HH).

Design

Prospective randomized crossover study.

Setting

A 16-bed medical intensive care unit (ICU).

Patients

Fifty patients receiving NIV for ARF.

Measurements

The effects of HME and HH on respiratory rate, minute ventilation, EtCO₂, oxygen saturation, airway occlusion pressure at 0.1 s, ABG, and comfort perception were compared during two randomly determined NIV periods of 30 min. The relative impact of HME and HH on these parameters was successively compared with or without addition of a flex tube (40 and 10 patients, respectively).

Main results

No difference was observed between HME and HH regarding any of the studied parameters, whether or not a flex tube was added.

Conclusion

If one decides to humidify patients’ airways during NIV, one may do so with small dead space HME or HH without altering respiratory parameters.     

Impact of the humidification device on intubation rate during noninvasive ventilation with ICU ventilators: results of a multicenter randomized controlled trial

Purpose

The use of heat and moisture exchangers (HME) during noninvasive ventilation (NIV) can increase the work of breathing, decrease alveolar ventilation, and deliver less humidity in comparison with heated humidifiers (HH). We tested the hypothesis that the use of HH during NIV with ICU ventilators for patients with acute respiratory failure would decrease the rate of intubation (primary endpoint) as compared with HME.

Methods

We conducted a multicenter randomized controlled study in 15 centers. After stratification by center and type of respiratory failure (hypoxemic or hypercapnic), eligible patients were randomized to receive NIV with HH or HME.

Results

Of the 247 patients included, 128 patients were allocated to the HME group and 119 to the HH group. Patients were comparable at baseline. The intubation rate was not significantly different: 29.7 % in the HME group and 36.9 % in the HH group (p = 0.28). PaCO₂ did not significantly differ between the two arms, even in the subgroup of hypercapnic patients. No significant difference was observed for NIV duration, ICU and hospital LOS, or ICU mortality (HME 14.1 vs. HH 21.5 %, p = 0.18).

Conclusions

In this study, the short-term physiological benefits of HH in comparison with HME during NIV with ICU ventilators were not observed, and no difference in intubation rate was found. The physiologic effects may have been obscured by leaks or other important factors in the clinical settings. This study does not support the recent recommendation favoring the use of HH during NIV with ICU ventilators.     

Six-month prognosis of patients with lung cancer admitted to the intensive care unit

Background

Intensive care unit (ICU) admission of patients with lung cancer remains debated because of the poor short-term prognosis. However, ICU admission of such patients should also be assessed on the possibility to administer specific anticancer treatment and the long-term outcome thereafter.

Objectives

To identify predictive factors of hospital and 6-month mortality in critically ill lung-cancer patients.

Design and setting

Retrospective study conducted in the ICU of a university hospital.

Patients

One hundred five consecutive lung-cancer patients included between 1 January 1997 and 31 December 2006.

Interventions

None.

Results

Of the 105 patients (mean age 64.8 years), 87 (83%) had a non-small cell lung cancer (NSCLC). Extensive disease was diagnosed in 85 patients (83%) (NSCLC stages IIIB and IV or disseminated small cell lung cancer). The main reasons for ICU admission were acute respiratory failure (59%) and/or hemoptysis (45%). Forty-three patients (41%) needed mechanical ventilation (MV). The ICU, hospital and 6-month mortality rates were 43, 54 and 73%, respectively. A performance status (PS) ≥2 [odds ratio OR = 3.6 (95% confidence interval CI (1.5–8.7)] and acute respiratory failure [OR = 3.5 (95% CI (1.5–8.4)] predicted hospital mortality. In a multivariate Cox model, the cancer progression [hazard ratio HR = 6.1 (95% CI 2.2–17)] and the need for MV [HR = 3.6 (95% CI 1.35–9.4)] were independently associated with 6-month mortality. Two-thirds of the ICU survivors were able to receive anticancer treatment.

Conclusions

ICU admission should be considered in selected patients with lung cancer (PS <2, no cancer disease progression).     

Critically ill infants and children with influenza A (H1N1) in pediatric intensive care units in Argentina

Objective

To determine the epidemiological features, course, and outcomes of critically ill pediatric patients with Influenza A (H1N1) virus.

Design

Prospective cohort of children in pediatric intensive care units (PICUs) due to Influenza A (H1N1) virus infection.

Setting

Seventeen medical-surgical PICUs in tertiary care hospital in Argentina.

Patients

All consecutive patients admitted to the PICUs with influenza A (H1N1) viral infection from 15 June to 31 July 2009.

Measurements and main results

Of 437 patients with acute lower respiratory infection in PICUs, 147 (34%) were diagnosed with influenza A (H1N1) related to critical illness. The median age of these patients was 10 months (IQR 3–59). Invasive mechanical ventilation was used in 117 (84%) on admission. The rate of acute respiratory distress syndrome (ARDS) was 80% (118 of 147 patients). Initial non-invasive ventilation failed in 19 of 22 attempts (86%). Mortality at 28 days was 39% (n = 57). Chronic complex conditions (CCCs), acute renal dysfunction (ARD) and ratio PaO₂/FiO₂ at day 3 on MV were independently associated with a higher risk of mortality. The odds ratio (OR) for CCCs was 3.06, (CI 95% 1.36–6.84); OR for ARD, 3.38, (CI 95% 1.45–10.33); OR for PaO₂/FiO₂, 4 (CI 95% 1.57–9.59). The administration of oseltamivir within 24 h after admission had a protective effect: OR 0.2 (CI 95% 0.07–0.54).

Conclusions

In children with ARDS, H1N1 as an etiologic agent confers high mortality, and the presence of CCCs in such patients increases the risk of death.     

Avoiding invasive mechanical ventilation by extracorporeal carbon dioxide removal in patients failing noninvasive ventilation

Purpose

To evaluate whether extracorporeal carbon dioxide removal by means of a pumpless extracorporeal lung-assist (PECLA) device could be an effective and safe alternative to invasive mechanical ventilation in patients with chronic pulmonary disease and acute hypercapnic ventilatory failure not responding to noninvasive ventilation (NIV).

Methods

In this multicentre, retrospective study, 21 PECLA patients were compared with respect to survival and procedural outcomes to 21 matched controls with conventional invasive mechanical ventilation. Matching criteria were underlying diagnosis, age, Simplified Acute Physiology Score II and pH at ICU admission.

Results

Of the 21 patients treated with PECLA, 19 (90?%) did not require intubation. Median PaCO₂ levels and pH in arterial blood prior to PECLA were 84.0?mmHg (54.2–131.0) and 7.28 (7.10–7.41), respectively. Within 24?h, median PaCO₂ levels and pH had significantly improved to 52.1 (33.0–70.1; p? p? p?=?0.056). There was no group difference in the 28-day (24?% vs. 19?%, adjusted p?=?0.845) or 6-month mortality (33?% vs. 33?%).

Conclusions

In this study the use of extracorporeal carbon dioxide removal allowed avoiding intubation and invasive mechanical ventilation in the majority of patients with acute on chronic respiratory failure not responding to NIV. Compared to conventional invasive ventilation, short- and long-term survivals were similar.     

A novel adaptive control system for noisy pressure-controlled ventilation: a numerical simulation and bench test study

Purpose

There is growing interest in the use of both variable and pressure-controlled ventilation (PCV). The combination of these approaches as “noisy PCV” requires adaptation of the mechanical ventilator to the respiratory system mechanics. Thus, we developed and evaluated a new control system based on the least-mean-squares adaptive approach, which automatically and continuously adjusts the driving pressure during PCV to achieve the desired variability pattern of tidal volume (V _T).

Methods

The controller was tested during numerical simulations and with a physical model reproducing the mechanical properties of the respiratory system. We applied step changes in respiratory system mechanics and mechanical ventilation settings. The time needed to converge to the desired V _T variability pattern after each change (t _c) and the difference in minute ventilation between the measured and target pattern of V _T (ΔMV) were determined.

Results

During numerical simulations, the control system for noisy PCV achieved the desired variable V _T pattern in less than 30 respiratory cycles, with limited influence of the dynamic elastance (E*) on t _c, except when E* was underestimated by >25%. We also found that, during tests in the physical model, the control system converged in <60 respiratory cycles and was not influenced by airways resistance. In all measurements, the absolute value of ΔMV was <25%.

Conclusion

The new control system for noisy PCV can prove useful for controlled mechanical ventilation in the intensive care unit.     

Increase in use of non-invasive ventilation for infants with severe bronchiolitis is associated with decline in intubation rates over a decade

Purpose

To redress the paucity of studies evaluating non-invasive respiratory support in bronchiolitis patients.

Methods

Following ethics committee approval, the clinical database of a tertiary 23-bed paediatric intensive care unit (PICU) was reviewed for bronchiolitis admissions from January 2000 to December 2009. Length of stay (LOS), ventilatory requirements and risk factors, including prematurity, respiratory syncytial virus (RSV) status, chronic lung, neuromuscular, immune and congenital heart disease, were analysed.

Results

Of 8,288 admissions, 520 (6.27?%) had bronchiolitis with 343 (65.9?%) having RSV. Median (±SD) age and LOS were 2.78?months and 2.68 (±4.32)?days. One (0.2?%) patient died. Assisted ventilation was required for 399 (76.7?%) patients. A total of 114 (28.6?%) patients were intubated directly and 285 (71.4?%) had a trial of non-invasive ventilation (NIV). Significant increase in the use of NIV was seen (2.8?%/year) with decline in intubation rates (1.9?%/ year) (p?=?0.002). Of NIV patients, 237 (83.2?%) needed only NIV and 48 (16.8?%) failed and therefore needed intubation. The median LOS was shorter in those who succeeded NIV (2.38?±?2.43?days) compared to those with invasive ventilation (5.19?±?6.34?days) and those who failed NIV (8.41?±?3.44?days). Presence of a risk factor increased the chances of failing NIV from 6 to 10?%.

Conclusion

NIV was successful in the vast majority of patients, particularly in those without risk factors and halved the LOS in intensive care. Failure of NIV was associated with increased duration of invasive ventilation and PICU LOS. A prospective study comparing different techniques of NIV will be helpful in defining the risks of failure of NIV.     

Clinical outcomes of patients requiring ventilatory support in Brazilian intensive care units: a multicenter,prospective, cohort study

Introduction

Contemporary information on mechanical ventilation (MV) use in emerging countries is limited. Moreover, most epidemiological studies on ventilatory support were carried out before significant developments, such as lung protective ventilation or broader application of non-invasive ventilation (NIV). We aimed to evaluate the clinical characteristics, outcomes and risk factors for hospital mortality and failure of NIV in patients requiring ventilatory support in Brazilian intensive care units (ICU).

Methods

In a multicenter, prospective, cohort study, a total of 773 adult patients admitted to 45 ICUs over a two-month period requiring invasive ventilation or NIV for more than 24 hours were evaluated. Causes of ventilatory support, prior chronic health status and physiological data were assessed. Multivariate analysis was used to identifiy variables associated with hospital mortality and NIV failure.

Results

Invasive MV and NIV were used as initial ventilatory support in 622 (80%) and 151 (20%) patients. Failure with subsequent intubation occurred in 54% of NIV patients. The main reasons for ventilatory support were pneumonia (27%), neurologic disorders (19%) and non-pulmonary sepsis (12%). ICU and hospital mortality rates were 34% and 42%. Using the Berlin definition, acute respiratory distress syndrome (ARDS) was diagnosed in 31% of the patients with a hospital mortality of 52%. In the multivariate analysis, age (odds ratio (OR), 1.03; 95% confidence interval (CI), 1.01 to 1.03), comorbidities (OR, 2.30; 95% CI, 1.28 to 3.17), associated organ failures (OR, 1.12; 95% CI, 1.05 to 1.20), moderate (OR, 1.92; 95% CI, 1.10 to 3.35) to severe ARDS (OR, 2.12; 95% CI, 1.01 to 4.41), cumulative fluid balance over the first 72 h of ICU (OR, 2.44; 95% CI, 1.39 to 4.28), higher lactate (OR, 1.78; 95% CI, 1.27 to 2.50), invasive MV (OR, 2.67; 95% CI, 1.32 to 5.39) and NIV failure (OR, 3.95; 95% CI, 1.74 to 8.99) were independently associated with hospital mortality. The predictors of NIV failure were the severity of associated organ dysfunctions (OR, 1.20; 95% CI, 1.05 to 1.34), ARDS (OR, 2.31; 95% CI, 1.10 to 4.82) and positive fluid balance (OR, 2.09; 95% CI, 1.02 to 4.30).

Conclusions

Current mortality of ventilated patients in Brazil is elevated. Implementation of judicious fluid therapy and a watchful use and monitoring of NIV patients are potential targets to improve outcomes in this setting.

Trial registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01268410","term_id":"NCT01268410"}}NCT01268410.     

Non-invasive ventilation as a strategy for weaning from invasive mechanical ventilation: a systematic review and Bayesian meta-analysis

Purpose

A systematic review and meta-analysis was conducted to answer the question ‘In adults with respiratory failure requiring invasive ventilation for more than 24 h, does a weaning strategy with early extubation to non-invasive ventilation (NIV) compared to invasive ventilation weaning reduce all-cause hospital mortality?’

Methods

We included randomised and quasi-randomised controlled trials that evaluated the use of non-invasive ventilation, compared to invasive ventilation, as a weaning strategy in adults mechanically ventilated for at least 24 h. The EMBASE, MEDLINE and Cochrane Central Register of Controlled Trials (CENTRAL) bibliographic databases were searched from inception to February 2018. Bayesian hierarchical models were used to perform the meta-analysis. The primary outcome was mortality at hospital discharge. Secondary outcomes included mortality (30, 60, 90 and 180 days), quality of life, duration of invasive ventilation, weaning failure, length of stay [intensive care unit (ICU) and hospital] and adverse events.

Results

Twenty-five relevant studies involving 1609 patients were included in the quantitative analysis. Studies had moderate to high risk of bias due to risk of performance and detection bias. Mortality at hospital discharge was lower in the NIV weaning group compared to the invasive weaning group [pooled odds ratio (OR) 0.58, 95% highest density interval (HDI) 0.29–0.89]. Subgroup analyses showed lower pooled mortality at hospital discharge rates in NIV weaning than those in the control group in chronic obstructive pulmonary disease (COPD) patients (pooled OR 0.43, 95% HDI 0.13–0.81) and the effect is less certain in the mixed ICU population (pooled OR 0.88, 95% HDI 0.25–1.48). NIV weaning reduced the duration of invasive ventilation in patients [standardised mean difference (SMD) ??1.34, 95% HDI ??1.92 to ??0.77] and ICU length of stay (SMD ??0.70, 95% HDI ??0.94 to ??0.46). Reported rates of ventilator associated pneumonia (VAP) were lower in the NIV group. NIV weaning did not reduce overall hospital length of stay or long-term mortality. There were insufficient data to compare other adverse events and health-related quality of life.

Conclusions

The use of NIV in weaning from mechanical ventilation decreases hospital mortality, the incidence of VAP and ICU length of stay. NIV as a weaning strategy appears to be most beneficial in patients with COPD.

     

Apnoeic oxygenation via high-flow nasal cannula oxygen combined with non-invasive ventilation preoxygenation for intubation in hypoxaemic patients in the intensive care unit: the single-centre,blinded, randomised controlled OPTINIV trial

Purpose

High-flow nasal cannula oxygen (HFNC) has the potential to provide apnoeic oxygenation. We decided to assess in a proof-of-concept study whether the addition of HFNC to non-invasive ventilation (NIV) could reduce oxygen desaturation during intubation, compared with NIV alone for preoxygenation, in severely hypoxaemic intensive care unit (ICU) patients with respiratory failure.

Methods

We conducted a randomised, controlled, single-centre trial with assessor-blinded outcome assessment in patients admitted to the ICU. Hypoxaemic patients requiring orotracheal intubation for respiratory failure were randomised to receive preoxygenation using HFNC [flow = 60 L/min, fraction of inspired oxygen (FiO₂) = 100 %] combined with NIV (pressure support = 10 cmH₂O, positive end-expiratory pressure = 5 cmH₂O, FiO₂ = 100 %) in the intervention group or NIV alone in the reference group prior to intubation. The primary outcome was the lowest oxygen saturation (SpO₂) during the intubation procedure. Secondary outcomes were intubation-related complications and ICU mortality.

Results

Between July 2015 and February 2016, we randomly assigned 25 and 24 patients to the intervention and reference groups, respectively. In both groups the main reasons for respiratory failure were pneumonia and ARDS. During the intubation procedure, the lowest SpO₂ values were significantly higher in the intervention group than in the reference group [100 (95–100) % vs. 96 (92–99) %, p = 0.029]. After exclusion of two patients from analysis for protocol violation, no (0 %) patients in the intervention group and five (21 %) patients in the reference group had SpO₂ below 80 % (p = 0.050). We recorded no significant difference between the groups in intubation-related complications or ICU mortality.

Conclusions

A novel strategy for preoxygenation in hypoxaemic patients, adding HFNC for apnoeic oxygenation to NIV prior to orotracheal intubation, may be more effective in reducing the severity of oxygen desaturation than the reference method using NIV alone.

     

Noninvasive mechanical ventilation in patients having declined tracheal intubation

Purpose

Noninvasive ventilation (NIV) is a treatment option in patients with acute respiratory failure who are good candidates for intensive care but have declined tracheal intubation. The aim of our study was to report outcomes after NIV in patients with a do-not-intubate (DNI) order.

Methods

Prospective observational cohort study in all patients who received NIV for acute respiratory failure in 54 ICUs in France and Belgium, in 2010/2011.

Results

Goals of care, comfort, and vital status were assessed daily. On day 90, a telephone interview with patients and relatives recorded health-related quality of life (HRQOL), posttraumatic stress disorder-related symptoms, and symptoms of anxiety and depression. Post-ICU burden was compared between DNI patients and patients receiving NIV with no treatment-limitation decisions (TLD). Of 780 NIV patients, 574 received NIV with no TLD, and 134 had DNI orders. Hospital mortality was 44 % in DNI patients and 12 % in the no-TLD group. Mortality in the DNI group was lowest in COPD patients compared to other patients in the DNI group (34 vs. 51 %, P = 0.01). In the DNI group, HRQOL showed no significant decline on day 90 compared to baseline; day-90 data of patients and relatives did not differ from those in the no-TLD group.

Conclusions

Do-not-intubate status was present among one-fifth of ICU patients who received NIV. DNI patients who were alive on day 90 experienced no decrease in HRQOL compared to baseline. The prevalences of anxiety, depression, and PTSD-related symptoms in these patients and their relatives were similar to those seen after NIV was used as part of full-code management (clinicaltrial.govNCT01449331).     

Early postoperative prophylactic noninvasive ventilation after major lung resection in COPD patients: a randomized controlled trial

Objectives

To investigate whether prophylactic postoperative NIV prevents respiratory complications following lung resection surgery in COPD patients.

Methods

In seven thoracic surgery departments, 360 COPD patients undergoing lung resection surgery were randomly assigned to two groups: conventional postoperative treatment without (n = 179) or with (n = 181) prophylactic NIV, applied intermittently during 6 h per day for 48 h following surgery. The primary endpoint was the rate of acute respiratory events (ARE) at 30 days postoperatively (ITT analysis). Secondary endpoints were acute respiratory failure (ARF), intubation rate, mortality rate, infectious and non-infectious complications, and duration of ICU and hospital stay.

Measurements and main results

ARE rates did not differ between the prophylactic NIV and control groups (57/181, 31.5 vs. 55/179, 30.7 %, p = 0.93). ARF rate was 18.8 % in the prophylactic NIV group and 24.5 % in controls (p = 0.20). Re-intubation rates were similar in the prophylactic NIV and control group [10/181 (5.5 %) and 13/179 (7.2 %), respectively, p = 0.53]. Mortality rates were 5 and 2.2 % in the control and prophylactic NIV groups, respectively (p = 0.16). Infectious and non-infectious complication rates, and duration of ICU and hospital stays were similar between groups.

Conclusions

Prophylactic postoperative NIV did not reduce the rate of ARE in COPD patients undergoing lung resection surgery and did not influence other postoperative complications rates, mortality rates, and duration of ICU and hospital stay.     

Noninvasive ventilation in chest trauma: systematic review and meta-analysis

Purpose

Single studies of Noninvasive Ventilation (NIV) in the management of acute respiratory failure in chest trauma patients have produced controversial findings. The aim of this study is to critically review the literature to investigate whether NIV reduces mortality, intubation rate, length of stay and complications in patients with chest trauma, compared to standard therapy.

Methods

We performed a systematic review and meta-analysis of randomized controlled trials, prospective and retrospective observational studies, by searching PubMed, EMBASE and bibliographies of articles retrieved. We screened for relevance studies that enrolled adults with chest trauma who developed mild to severe acute respiratory failure and were treated with NIV. We included studies reporting at least one clinical outcome of interest to perform a meta-analysis.

Results

Ten studies (368 patients) met the inclusion criteria and were included for the meta-analysis. Five studies (219 patients) reported mortality and results were quite homogeneous across studies, with a summary relative risk for patients treated with NIV compared with standard care (oxygen therapy and invasive mechanical ventilation) of 0.26 (95 % confidence interval 0.09–0.71, p = 0.003). There was no advantage in mortality of continuous positive airway pressure over noninvasive pressure support ventilation. NIV significantly increased arterial oxygenation and was associated with a significant reduction in intubation rate, in the incidence of overall complications and infections.

Conclusions

These results suggest that NIV could be useful in the management of acute respiratory failure due to chest trauma.     

The ETHICA study (part II): simulation study of determinants and variability of ICU physician decisions in patients aged 80 or over

Purpose

To assess physician decisions about ICU admission for life-sustaining treatments (LSTs).

Methods

Observational simulation study of physician decisions for patients aged ≥80 years. Each patient was allocated at random to four physicians who made decisions based on actual bed availability and existence of an additional bed before and after obtaining information on patient preferences. The simulations involved non-invasive ventilation (NIV), invasive mechanical ventilation (IMV), and renal replacement therapy after a period of IMV (RRT after IMV).

Results

The physician participation rate was 100/217 (46 %); males without religious beliefs predominated, and median ICU experience was 9 years. Among participants, 85.7, 78, and 62 % felt that NIV, IMV, or RRT (after IMV) was warranted, respectively. By logistic regression analysis, factors associated with admission were age <85 years, self-sufficiency, and bed availability for NIV and IMV. Factors associated with IMV were previous ICU stay (OR 0.29, 95 % CI 0.13–0.65, p = 0.01) and cancer (OR 0.23, 95 % CI 0.10–0.52, p = 0.003), and factors associated with RRT (after IMV) were living spouse (OR 2.03, 95 % CI 1.04–3.97, p = 0.038) and respiratory disease (OR 0.42, 95 % CI 0.23–0.76, p = 0.004). Agreement among physicians was low for all LSTs. Knowledge of patient preferences changed physician decisions for 39.9, 56, and 57 % of patients who disagreed with the initial physician decisions for NIV, IMV, and RRT (after IMV) respectively. An additional bed increased admissions for NIV and IMV by 38.6 and 13.6 %, respectively.

Conclusions

Physician decisions for elderly patients had low agreement and varied greatly with bed availability and knowledge of patient preferences.     

The feasibility and safety of extracorporeal carbon dioxide removal to avoid intubation in patients with COPD unresponsive to noninvasive ventilation for acute hypercapnic respiratory failure (ECLAIR study): multicentre case–control study

Introduction

The aim of the study was to evaluate the feasibility and safety of avoiding invasive mechanical ventilation (IMV) by using extracorporeal CO₂ removal (ECCO₂R) in patients with acute exacerbation of chronic obstructive pulmonary disease (COPD) and acute hypercapnic respiratory failure refractory to noninvasive ventilation (NIV).

Methods

Case–control study. Patients with acute hypercapnic respiratory failure refractory to NIV being treated with a pump-driven veno-venous ECCO₂R system (iLA-Activve^®; Novalung, Heilbronn, Germany) were prospectively observed in five European intensive care units (ICU). Inclusion criteria were respiratory acidosis (pH ≤ 7.35, PaCO₂ > 45 mmHg) with predefined criteria for endotracheal intubation (ClinicalTrials.gov NCT01784367). The historical controls were patients with acute hypercapnic respiratory failure refractory to NIV who were treated with IMV. The matching criteria were main diagnosis, age, SAPS-II score and pH.

Results

Twenty-five cases (48.0 % male, mean age 67.3 years) were matched with 25 controls. Intubation was avoided in 14 patients (56.0 %) in the ECCO₂R group with a mean extracorporeal blood flow of 1.3 L/min. Seven patients were intubated because of progressive hypoxaemia and four owing to ventilatory failure despite ECCO₂R and NIV. Relevant ECCO₂R-associated adverse events were observed in 11 patients (44.0 %), of whom 9 (36.0 %) suffered major bleeding complications. The mean time on IMV, ICU stay and hospital stay in the case and control groups were 8.3 vs. 13.7, 28.9 vs. 24.0 and 36.9 vs. 37.0 days, respectively, and the 90-day mortality rates were 28.0 vs. 28.0 %.

Conclusions

The use of veno-venous ECCO₂R to avoid invasive mechanical ventilation was successful in just over half of the cases. However, relevant ECCO₂R-associated complications occurred in over one-third of cases. Despite the shorter period of IMV in the ECCO₂R group there were no significant differences in length of stay or in 28- and 90-day mortality rates between the two groups. Larger, randomised studies are warranted for further assessment of the effectiveness of ECCO₂R.

     

The Italian ECMO network experience during the 2009 influenza A(H1N1) pandemic: preparation for severe respiratory emergency outbreaks

Purpose

In view of the expected 2009 influenza A(H1N1) pandemic, the Italian Health Authorities set up a national referral network of selected intensive care units (ICU) able to provide advanced respiratory care up to extracorporeal membrane oxygenation (ECMO) for patients with acute respiratory distress syndrome (ARDS). We describe the organization and results of the network, known as ECMOnet.

Methods

The network consisted of 14 ICUs with ECMO capability and a national call center. The network was set up to centralize all severe patients to the ECMOnet centers assuring safe transfer. An ad hoc committee defined criteria for both patient transfer and ECMO institutions.

Results

Between August 2009 and March 2010, 153 critically ill patients (53% referred from other hospitals) were admitted to the ECMOnet ICU with suspected H1N1. Sixty patients (48 of the referred patients, 49 with confirmed H1N1 diagnosis) received ECMO according to ECMOnet criteria. All referred patients were successfully transferred to the ECMOnet centers; 28 were transferred while on ECMO. Survival to hospital discharge in patients receiving ECMO was 68%. Survival of patients receiving ECMO within 7?days from the onset of mechanical ventilation was 77%. The length of mechanical ventilation prior to ECMO was an independent predictor of mortality.

Conclusions

A network organization based on preemptive patient centralization allowed a high survival rate and provided effective and safe referral of patients with severe H1N1-suspected ARDS.     

The effects of increasing effective airway diameter on weaning from mechanical ventilation in tracheostomized patients: a randomized controlled trial

Purpose

To determine the effects of deflating the tracheal cuff during disconnections from mechanical ventilation (MV) in tracheostomized patients.

Methods

This was a single-center, randomized trial conducted in a general ICU of a tertiary hospital with regional referral for trauma patients. Patients at high risk of aspiration based on the drink test were excluded. Critically ill tracheostomized patients were randomized to have the tracheal cuff deflated or not during spontaneous breathing trials. Weaning was protocolized on progressive T-tube trials, and patients were considered weaned after 24 consecutive hours disconnected from MV. The primary end point was time to definitive withdrawal of MV; secondary end points were ventilator-associated respiratory infection (pneumonia and/or tracheobronchitis) and swallowing function. Statistical analyses included Cox proportional risk models.

Results

We randomized 195 patients and 181 patients completed the study (94 patients with deflated cuff and 87 with inflated cuff). Variables independently related to weaning time in the multivariate analysis were tracheostomy-to-first MV disconnection time (HR 0.5, 95 % CI 0.3–0.8; p < 0.01) and cuff deflation (HR 2.2, 95 % CI 1.5–3; p < 0.01). Respiratory infection was lower in the deflated group (20 vs. 36 %; p = 0.02). Swallowing function improved more in the deflated group (31 vs. 22 %; p = 0.02).

Conclusion

Under the conditions of our protocol, deflating the tracheal cuff in tracheostomized patients shortens weaning, reduces respiratory infections, and probably improves swallowing.     

Elevation of creatine kinase is associated with worse outcomes in 2009 pH1N1 influenza?A infection

Background

Current medical knowledge lacks specific information regarding creatine kinase (CK) elevation in influenza?A pH1N1 (2009) infection.

Objectives

Primary endpoints were correlation between CK at intensive care unit (ICU) admission and ICU mortality. Secondary endpoints were ICU length of stay (LOS), mechanical ventilation (MV), and requirement of renal replacement techniques (RRT).

Materials and methods

A prospective multicenter register included all adults admitted for severe acute respiratory insufficiency (SARI) with confirmed pH1N1 in 148 ICUs. Clinical data including demographics, comorbidities, laboratory information, organ involvement, and prognostic data were registered. Post?hoc classification of subjects was determined according to CK level. Data are expressed as median (interquartile range).

Results

Five hundred and five (505) patients were evaluable. Global ICU mortality was 17.8?% without documented differences between breakpoints. CK ≥500?UI/L was documented in 23.8?% of ICU admissions, being associated with greater renal dysfunction: acute kidney injury (AKI) was more frequent (26.1 versus 17.1?%, p?p?p?p?=?0.07) and duration of mechanical ventilation (median 15?days versus 11?days, p?Conclusions CK is a biomarker of severity in pH1N1 infection. Elevation of CK was associated with more complications and increased ICU LOS and healthcare resources.     

Outcomes of mechanically ventilated hematology patients with invasive pulmonary aspergillosis

Background

Invasive pulmonary aspergillosis (IPA) is a life-threatening infection documented in up to 15% of hematology patients who require intensive care for acute respiratory failure. We report outcomes in hematology patients given mechanical ventilation (MV) with IPA.

Methods

Retrospective study of all hematology patients given MV with IPA between January 1998 and March 2011 at a single center. Predictors of 6-month survival or mortality were identified using multivariable analysis.

Results

We studied 67 patients including 49 (73%) with neutropenia, 23 (34%) with long-term steroid therapy, and 14 (21%) with allogeneic bone marrow transplantation. Incidence of IPA in the ICU decreased between 1998 and 2011, and mortality in patients receiving mechanical ventilation did not change. IPA was confirmed in 6 patients by autopsy and was probable in 61 patients based on host factors, clinical and radiographic features, and either Aspergillus isolation (50 patients) or Aspergillus antigen detection alone (11 patients). Concomitant bacterial infections were documented in 24 (36%) patients. ICU and 6-month mortality rates were 67 and 82%, respectively. Mortality was stable throughout the study period. Concomitant bacterial infection was independently associated with higher mortality [HR, 2.1 (1.2?C3.8)]. Mortality was lower in patients given voriconazole [OR, 0.5 (0.3?C0.9)].

Conclusion

Hospital mortality remains high in hematology patients requiring MV with IPA, particularly when concommittant infection occurred. The use of voriconazole improved survival.     

Noninvasive ventilation immediately after extubation improves weaning outcome after acute respiratory failure: a randomized controlled trial

Introduction

Noninvasive ventilation (NIV), as a weaning-facilitating strategy in predominantly chronic obstructive pulmonary disease (COPD) mechanically ventilated patients, is associated with reduced ventilator-associated pneumonia, total duration of mechanical ventilation, length of intensive care unit (ICU) and hospital stay, and mortality. However, this benefit after planned extubation in patients with acute respiratory failure of various etiologies remains to be elucidated. The aim of this study was to determine the efficacy of NIV applied immediately after planned extubation in contrast to oxygen mask (OM) in patients with acute respiratory failure (ARF).

Methods

A randomized, prospective, controlled, unblinded clinical study in a single center of a 24-bed adult general ICU in a university hospital was carried out in a 12-month period. Included patients met extubation criteria with at least 72 hours of mechanical ventilation due to acute respiratory failure, after following the ICU weaning protocol. Patients were randomized immediately before elective extubation, being randomly allocated to one of the study groups: NIV or OM. We compared both groups regarding gas exchange 15 minutes, 2 hours, and 24 hours after extubation, reintubation rate after 48 hours, duration of mechanical ventilation, ICU length of stay, and hospital mortality.

Results

Forty patients were randomized to receive NIV (20 patients) or OM (20 patients) after the following extubation criteria were met: pressure support (PSV) of 7 cm H₂O, positive end-expiratory pressure (PEEP) of 5 cm H₂O, oxygen inspiratory fraction (FiO₂) ≤ 40%, arterial oxygen saturation (SaO₂) ≥ 90%, and ratio of respiratory rate and tidal volume in liters (f/TV) < 105. Comparing the 20 patients (NIV) with the 18 patients (OM) that finished the study 48 hours after extubation, the rate of reintubation in NIV group was 5% and 39% in OM group (P = 0.016). Relative risk for reintubation was 0.13 (CI = 0.017 to 0.946). Absolute risk reduction for reintubation showed a decrease of 33.9%, and analysis of the number needed to treat was three. No difference was found in the length of ICU stay (P = 0.681). Hospital mortality was zero in NIV group and 22.2% in OM group (P = 0.041).

Conclusions

In this study population, NIV prevented 48 hours reintubation if applied immediately after elective extubation in patients with more than 3 days of ARF when compared with the OM group.

Trial Registration number

ISRCTN: 41524441.